Fix that stupid rootdir workaround since it's causing trouble

[DanielG]

See vim-syntastic/syntastic#1576

ghc-mod since 5.4 needs to be run in the directory returned by ghc-mod root. This is an ugly woraround for a race condition in the code, we really should fix the cause instead.

We start generating the symbol table for find asyncrounously when running legacy-interactive most of the code is here: https:/kazu-yamamoto/ghc-mod/blob/master/src/Misc.hs The race condition comes from the fact that we use runGhcModT twice: once in the main thread, once in the async symboldb thing.

[DanielG]

Fixed in 7bbaa35